Question

Click to see problem explain by Image 我有两种形式...... 在form1上有一个提交按钮，当按下form2时应该打开用户名文本框和提交按钮.... 当用户按下提交按钮时，form1将再次出现，按钮文本将更改为用户名，并且将出现新的注册按钮....

它适用于第一次按，但在第二个按钮按下第一个按钮文本转到默认文本，如何解决这个问题？

第1课

namespace Internship_Test
{
    public partial class Form1 : Form
    {

        public Form1()
        {
            InitializeComponent();


        }    

        public string b;

        public Form1(Form2 obj)
        {
            InitializeComponent();
            if(button1.Name == obj.b2)
            {
                button1.Text = obj.username;
                button2.Visible = true;

            }
            else if(button2.Name == obj.b2)
            {

                button2.Visible = true;
                button2.Text = obj.username;
                button3.Visible = true;
            }
            else if (button3.Name == obj.b2)
            {
                button2.Visible = true;
                button3.Visible = true;
                button3.Text = obj.username;
                button4.Visible = true;
            }
            else if (button4.Name == obj.b2)
            {
                button2.Visible = true;
                button3.Visible = true;
                button4.Visible = true;
                button4.Text = obj.username;
                button5.Visible = true;
            }
            else if (button4.Name == obj.b2)
            {
                button2.Visible = true;
                button3.Visible = true;
                button4.Visible = true;
                button5.Visible = true;
                button5.Text = obj.username;
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.b = ((Button)sender).Name;
            Form2 obj = new Form2(this);
            obj.ShowDialog();
            this.Hide();

        }
    }
}

第2课

namespace Internship_Test
{
    public partial class Form2 : Form
    {
        string[] user = new string[5];
        public Form2()
        {
            InitializeComponent();

        }
        public string b2;
        public Form2(Form1 obj)
        {
            InitializeComponent();
            b2 = obj.b;

        }

        public string username;

        private void button1_Click(object sender, EventArgs e)
        {
            username = textBox2.Text;
            Form1 obj = new Form1(this);
            obj.Show();
            this.Hide();
        }
    }
}[Click to see problem explain by Image ][1]

Answer 1

作为对你的问题/错误的回应，像Mong Zhu指出的那样：

您的错误可在此处找到：

class 2

namespace Internship_Test
{
    public partial class Form2 : Form
    {
        string[] user = new string[5];
        public Form2()
        {
            InitializeComponent();

        }
        public string b2;

        private Form1 _form1;   // you need to create a field for the form1

        public Form2(Form1 form1)
        {
            InitializeComponent();
            b2 = obj.b;
            _form1 = form1; 

        }

        public string username;

        private void button1_Click(object sender, EventArgs e)
        {
            username = textBox2.Text;
            //Form1 obj = new Form1(this);
            // instead of creating a new form, just pop it up:
            _form1?.Show();
            this.Hide();
        }
    }
}

您应该将obj.ShowDialog();更改为obj.Show();

Answer 2

有些问题：

你为什么要隐藏form1？
为什么要将Form2的实例传递给Form1的构造函数？

我会像：

那样实现它

public class Form1 : Form
{
    private void button1_Click(object sender, EventArgs e)
    {
        using(var form2 = new Form2())
        {
            // if you want to fill the username before popup..
            // do it here:
            // form2.UserName = textBox2.Text;

            var result = form2.ShowDialog();

            if(result != DialogResult.OK)
                return;

            textBox2.Text = form2.UserName;
        }
    }
}

public class Form2 : Form
{
    public string UserName
    {
        get { return textBox1.Text; }
        set { textBox1.Text = value; }
    }
}

在两个表单C＃之间发送数据

2 个答案: